In the aviation industry, in-flight refueling extends the range and endurance of aircraft without requiring the aircraft to land. Although in-flight refueling is a relatively common operation, especially for military aircraft, the aircraft to be refueled (e.g., the receiver aircraft) must be precisely positioned relative to the tanker aircraft to provide safe engagement while the fuel is dispensed to the receiver aircraft. The precise relative spatial positioning of the two rapidly moving aircraft makes in-flight refueling a challenging operation.
One type of in-flight refueling system includes a boom refueling system that includes a rigid boom extending from the tanker aircraft, with a probe and nozzle at its distal end. The boom includes airfoils (e.g., rudders) controlled by a boom operator stationed on the refueling aircraft. The airfoils allow the boom operator to actively maneuver the boom with respect to the receiver aircraft, which usually flies in a fixed refueling position below and aft of the tanker aircraft. The boom operator typically monitors the aerial refueling boom with video displays to assist with guiding the boom nozzle into the receptacle of the receiver aircraft.
Conventional video displays provide essential information to the boom operator for readily cross-checking the status of the refueling system including boom elevation, azimuth, telescoping length, boom state, and fuel delivery without obscuring or otherwise losing sight of the receiver aircraft. Warning indicators are positioned so as to attract the boom operator's attention when concentrating on positioning the boom nozzle in the receiver aircraft's receptacle, without compromising safety by obscuring essential areas of the scene.
Some conventional video displays provide visual overlays of this essential information in the form of linear scales, numeric fields, and warning indicators that are displayed at fixed locations in the displayed images. Generally, the visual overlays displayed over the images of the receiver aircraft obscure the boom operator's view of the receiver aircraft during the aerial refueling process, which is typically unsafe. In some instances, conventional overlays may obscure dangerous situations in aerial refueling, which may increase the occurrence of damage to the aerial refueling boom and receiver. As a result, there is a need for an improved system and method for providing visual overlays in displayed images of aerial refueling operations that improve safety.